Chemistry 12 Chapter 3 Exemplar Solutions Electrochemistry Part 6

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VI. Long Answer Type

Question 66:

Consider the Fig. 3.2 and answer the following questions.

Electrolytic cell

Electrolytic Cell

(i) Cell ‘A’ has and Cell ‘B’ has which of the two cells ‘A’ or ‘B’ will act as an electrolytic cell. Which electrode reactions will occur in this cell?

(ii) If cell ‘A’ has and cell ‘B’ has then what will be the reactions at anode and cathode?

Answer:

(i) Cell ‘B’ will act as electrolytic cell as it has lower

∴ The electrode reactions will be:

at cathode

at anode

(ii) Now cell ‘B’ acts as galvanic cell as it has higher and will push electrons into cell ‘A’.

The electrode reaction will be:

At

At cathode:

Question 67:

Consider Fig. 3.2 and answer the questions (i) to (vi) given below.

Electron flow

Electron Flow

(i) Redraw the diagram to show the direction of electron flow.

(ii) Is silver plate the anode or cathode?

(iii) What will happen if salt bridge is removed?

(iv) When will the cell stop functioning?

(v) How will concentration of ions and ions be affected when the cell functions?

(vi) How will the concentration of ions and ions be affected after the cell becomes ‘dead’?

Answer:

Hint:

(i) Electrons move from to .

(ii) is the cathode.

(iii) Cell will stop functioning.

(iv) When .

(v) Concentration of ions will increase and concentration of will decrease

(vi) When equilibrium is reached and concentration of ions and ions will not change.

Question 68:

What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the of the cell? When will the maximum work be obtained from a galvanic cell?

Answer:

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